Various heat insulation structures and methods for insulating stop valves (including parallel-slide valves) are known in the art.
For example, a “Heat Insulation Structure” (disclosed by RF patent No. RU40433, published on Sep. 10, 2004, IPC F16L59/00) discloses a temporary heat insulation structure that includes removable segments of coverings that are fastened together with bands. The segments are assembled in a structure that forms a heat insulation jacket around the pipeline and consists of multiple sectors that are diametrically bound together using a lock. The bands are made in the form of tightening belts fixed with a tightening device with a stopper.
However, this structure does not allow for quick removal of individual segments. Access to individual components of insulated equipment for maintenance and repair requires dismantling of the entire structure which is undesirable.
A parallel-slide valve insulation device (disclosed by RF patent No. RU119843, published on Aug. 27, 2012, IPC F16L59/00) discloses temporary structures having a protective envelope. The inner surface of the envelope has a non-flammable insulating material attached via mastic. This reference is the closest analogue of the technical solution disclosed herein. The joints between the temporary components of the structure are sealed with sealing gaskets, providing access to the parallel-slide valve for maintenance and repair. The parallel-slide valve insulation design may consist of two or more parts, and its shape (rectangular or shaped version) is determined by the shape and size of the parallel-slide valve, design features, a type of connection to the pipeline (welded or flanged), and the mounting method. The protective envelope is made of galvanized sheet steel. Insulation parts are fixed with metal ties with locks, bolts with nuts, and self-tapping screws. The design has a non-removable (factory mounted) portion at the bottom of the parallel-slide and a part consisting of temporary components (installed in the field). Glass foam is used as insulation material. Inside the protective envelope with insulation there are gas detectors and pipe branches for blowing out the internal cavity of the heat insulation before dismantling when the gas detectors detect a high content of oil vapors.
The disadvantage of this solution is that it is a relative complicated design of a parallel-slide valve heat insulation relative to the solution. In particular, this design requires greater labor input during its installation and during maintenance while the pipeline is operating. Also, this design is characterized by a highly fragile heat insulation layer due to lack of mechanical protection of the heat insulation layer that is made of glass foam.